Seplos mason battery build [Should I get 2 x 5kWh or a 10kWh battery?]

...Ghost...

I have asked for 2 x 5.3kWh batteries in a final solar installation quote. I received a 10.4kWh single battery quote with the system, despite asking for 2 x 5.3kWh batteries.

The agreed price hasn't changed, but am I right to think it is more expensive to buy 2 x 5kWh batteries than a single 10kWh? The reason I want the 2 batteries, is that I might add a third 5kWh battery later in the year if it makes sense financially. I also want a modular setup, where I could stack 3 x 5kWh units together, or side by side. I don't know if it would be a problem mixing a 10 and a 5 together? Other than aesthetics, I presume not.

slave1

Okay, I'm going to bite.....what price because with almost 100% certainty you can build your own from either raw cells and a BMS or kits, for the same price to what you are currently paying you'd probably end up with a 20kWh battery.

...Ghost...

https://www.boards.ie/discussion/comment/121758281#Comment_121758281

€4,200 for WECO battery units. Same as the cheapest retail price I saw at solarboss.ie due to the No VAT situation.

I know I could build up a battery unit for less, but I have ruled that out for now.

on_the_roots

€4,200 can buy 2x Seplos Mason Kits + 32x Envision 305ah cells totalling 30kwh battery set. And this is not that difficult to put everything together.

...Ghost...

https://www.boards.ie/discussion/comment/121780593#Comment_121780593

I would have to see it being done before I would feel comfortable doing a DIY setup.

Calahonda52

https://www.boards.ie/discussion/comment/121780707#Comment_121780707

am sure there is plenty on screw tube

...Ghost...

https://www.boards.ie/discussion/comment/121780734#Comment_121780734

This is kind of what I want to avoid.

https://www.youtube.com/watch?v=igO3Q8lK7H0&ab_channel=Off-GridGarage

...Ghost...

https://www.boards.ie/discussion/comment/121780593#Comment_121780593

Can you link to these exact products? I will do some research.

I also think 20kWh of battery would be more than enough for me.

...Ghost...

I wonder would something like this be a happy medium between full DIY and Pro install?

https://seplos.en.alibaba.com/product/10000011813755-904752468/Seplos_ODM_Rechargeable_48V_51_1V_207Ah_10_57KWh_Home_Solar_Energy_Storage_System_NCM_Battery_Pack.html?spm=a2700.shop_index.9786.17.2e16730a5d3ZBL

I just don't want to go messing around with the system until I have a better understanding. However, If I can just connect one of these batteries to the hybrid inverter with minimal fuss and a couple settings changes, then I am OK with that.

graememk

Try looking at gobelpower too, it's a ready to go battery.

...Ghost...

https://www.boards.ie/discussion/comment/121781517#Comment_121781517

What about the one I linked above? I thought that was a ready to go battery. About €1k less for the 15kWh version than Gobel.

First time looking at these types of batteries, so I don't know what to look out for.

https://www.alibaba.com/product-detail/Seplos-MASON-230L-48V-230Ah-11_1600819750479.html?spm=a2700.wholesale.you_may_like.4.7c363611pZ6siH

graememk

https://www.boards.ie/discussion/comment/121781546#Comment_121781546

gobel power (same as the one reviewed on the off grid garage)

https://www.gobelpower.com/gobel-power-gpsr1pc200-512v-280ah-lifepo4-battery_p114.html

Work out what the cheapest/kWh and go from that, I see no obvious issue with the one you linked either

...Ghost...

https://www.boards.ie/discussion/comment/121781668#Comment_121781668

I think I will go for a DIY battery after looking more into it. Thanks for the nudge and thanks to @on_the_roots for mentioning it.

I like the idea of the DIY kits and I reckon I can handle that. I want to start with something like a 15kWh setup with a ready made vertical box. I need the battery to wall mount. I can make a bracket for this if need be, but I can't have it sticking out like an open drawer (server style) because this will be in a narrow side passage.

Can anyone advise on:

This DIY kit https://www.alibaba.com/product-detail/48V-DIY-Units-Battery-Box-Without_1600751118441.html?xp=FNr2dMcx2QkNAkApgG4PdDqUhm7EMbk6Am3HnO0c0vrw2Ol_5lTs8CcPo88De_uztMNZWCruKnKSM87By9k05FEH21x7QrJ-JITxfF6huJ8&cps_sk=rkj8oj9l&bm=cps&src=saf&productId=1600751118441

And what about these batteries (maybe I am paying too much with Grade A? https://www.gobelpower.com/ev-grade-a-eve-32v-280ah-rechargeable-lifepo4-battery-cell_p102.html?ref=ogga

I calculate that 16 of them should give me over 13kWh of storage. Do I need anything else?

The battery would be connected to a SOLIS hybrid inverter. I seen in the DIY battery thread something about setting the BMS to SOFAR and the battery name to AoBo or some other. Do I need any hardware, or software to do any of this? Thanks.

on_the_roots

https://www.boards.ie/discussion/comment/121781195#Comment_121781195

Cells:

https://eu.nkon.nl/rechargeable/lifepo4/prismatisch/envision-ess-72173207-305ah-lifepo4-3-2v-b-grade.html

Mason Kit (it also works with the 305ah cells):

https://www.fogstar.co.uk/collections/seplos-mason-kits/products/seplos-tall-48v-280ah-diy-kit-14-3kwh?variant=41178807173179

slave1

100% NKON versus AE, even though mine came from AE and are rock solid the NKON are more "local" and they have a better rep over more recent AE purchases

...Ghost...

https://www.boards.ie/discussion/comment/121787837#Comment_121787837

Cheers. One other thing (excuse my ignorance)...

NKON are B Grade Cells that you linked, which are about the same price as the A Grade Cells I linked from Gobel Power. What reason would I be choosing the NKON over the Gobel cells?

graememk

Its the shipping you also need to take into account, Although gobel are "A Rated"

...Ghost...

https://www.boards.ie/discussion/comment/121788286#Comment_121788286

At ~€270 more, are the "A Rated" cells worth the extra?

Works out at an extra €17ish Euro per cell.

Probably safer going with an EU supplier though and the B Grades wouldn't take so long to arrive.

Newtown90

https://www.boards.ie/discussion/comment/121781517#Comment_121781517

Can you order direct with Gobel or do you have to organise shipping yourself?

...Ghost...

https://www.boards.ie/discussion/comment/121789790#Comment_121789790

It was direct with Gobel. Shipping showed at checkout.

on_the_roots

https://www.boards.ie/discussion/comment/121788405#Comment_121788405

There is no actual difference between "A" and "B" grade cells for PV storage. The nature of this type of usage doesn't require very high charge/discharge performance like EVs, so "B" grade cells will work perfectly fine. Also you have NKON warranty on them, anything wrong and you are well covered.

...Ghost...

https://www.boards.ie/discussion/comment/121801392#Comment_121801392

Thanks. This is what I thought, but couldn't find a straight answer. That helps me with my decision.

...Ghost...

https://www.boards.ie/discussion/comment/121787837#Comment_121787837

There isn't an option to deliver the Seplos kit to Ireland. Have you ordered from frogstar before?

graememk

https://www.boards.ie/discussion/comment/121811670#Comment_121811670

Parcel depot in northern Ireland is the option for fogstar

on_the_roots

https://www.boards.ie/discussion/comment/121811670#Comment_121811670

I used Parcel Depot to receive it close to the border and I drove there to pick up. £48,00 for their service because this comes in a pallet.

The devils

https://www.boards.ie/discussion/comment/121818358#Comment_121818358

Super

Did you also order seplos battery and can cables for unit through fogstar?

on_the_roots

https://www.boards.ie/discussion/comment/121818668#Comment_121818668

No, you can get them from Nkon as well. I got this one.

The devils

https://www.boards.ie/discussion/comment/121819066#Comment_121819066

Thanks for that 👍

...Ghost...

https://www.boards.ie/discussion/comment/121818358#Comment_121818358

I plan to put in an order soon. Did you have to take the pallet, or can it be left with parcel depot. I wouldn't fit a pallet in the saloon.

The devils

https://www.boards.ie/discussion/comment/121903991#Comment_121903991

I'd say you have to keep the pallet , but asked before you order

graememk

https://www.boards.ie/discussion/comment/121903991#Comment_121903991

Time to bring a heavy hammer 😂

on_the_roots

https://www.boards.ie/discussion/comment/121903991#Comment_121903991

I didn't have to take the pallet with me. They mentioned this is ok for customers to leave them behind, not a hassle at all.

...Ghost...

https://www.boards.ie/discussion/comment/121907394#Comment_121907394

That's great, cheers. The V3, grade B vertical seplos DIY kit is out of stock. Ife asked fogstar for shipping weight and dimensions and when they would be back in stock. Hopefully soon.

SD_DRACULA

I was thinking of doing vertical battery cases too but Nkon suggested to NOT put the cells on their sides so maybe something to think about.

...Ghost...

https://www.boards.ie/discussion/comment/121911983#Comment_121911983

Unfortunately I don't have much choice, as my batteries are being located in the side alley which is only about 1100mm wide. I don't have the space for the rack style cases.

From everything I have watched, it is OK to put them in any orientation except upside down.

SD_DRACULA

I'd say just confirm with the cell manufacturer and should be fine if they say so.

olympicweights

https://www.boards.ie/discussion/comment/121907519#Comment_121907519

I must have gotten the last one, ordered on 17th!

oaklands

https://www.boards.ie/discussion/comment/121911983#Comment_121911983

A summary based on what i have read.....for LifePo4 Prismatic cells.

• Preferably vertical with terminals facing up...compression is suggested in data sheets
• Horizontal with the wide side down/up is OK....but compression & structural support is much more important in this case (compared to vertical).
• Horizontal with the narrow side down/up...a big no no.
• Terminals facing down... an even bigger no no.

...Ghost...

OK guys, I am ready to pull the trigger and order the SEPLOS Mason vertical DIY kit from Fogstar, delivered to NI.

I am also ready to order the B Cells from NKON.

I have the battery cables that came with the Solis Hybrid Inverter.

What else do I need to order so I can complete the build and installation? Fuses, cables, comms, bus bars…anything else? Last thing I want is to have it built and then have to wait weeks for more parts I should have ordered right away.

I'll be planning and building an insulated frame for up to 3 of these batteries while I wait for delivery.

cinuszek

https://www.boards.ie/discussion/comment/121978661#Comment_121978661

Hi Ghost, how is your DIY project doing?

...Ghost...

https://www.boards.ie/discussion/comment/122623624#Comment_122623624

It's going great. I built the first Seplos kit in the middle of June and put an installation video series out there for those following the same route. I drove to Germany at the end of July to collect my son and I picked up another set of batteries from NKON and another kit from Fogstar on my return. That battery was built and installed about 2 weeks ago, giving me around 26kWh useable storage.

I have them mounted inside insulated cabinets which are nearly finished. Will keep them efficient during the cold weather. My house is running off the batteries each day partially from solar and mostly from cheap night rate from the grid between 2 and 6am. I import next to nothing outside of the cheap rate and I export a lot of what I don't need/use.

I currently have the batteries daisy chained, but plan to go the busbar route to keep them charging and discharging equally. I'm dumping 10kWh excess every night from midnight and then topping up cheaply, plus whatever is exported if the batteries are full and the house load is small. Battery is right now 75% thanks to a sunny day adding to the tank and supporting the house load.

I plan to add a third battery and a DC-DC charger most likely before the end of the year.

Here's how they are at the moment, in the side passage. Still needs some finishing work, but all good so far. I had to get an electric hoist to lift them up onto the cabinet shelf as you can see from the pic.

I will also be adding more solar, but that's kinda separate to my battery project, even though the next 4 panels will be on the same inverter. I had already stretched over the budget with my planned 9 south facing panels. I ended up getting 8 south facing and bought an extra 3 panels for the north roof, plus the one that couldn't fit on the south roof. That was about an extra 1k with optimisers. I have room for 4 more panels on the north roof, but the installers quoted €2,200 plus VAT, so I will be doing it myself. Lots more plans in the head.

slave1

Got you hook, line and sinker☀️

mjatkey

Hi, yeah and might I add a great line up of videos. Do you get both batteries fully charged in the EV window, I see you have 26Kw charged so assuming you pretty much do?

What charge current do you have the Solis set on?

Thanks

...Ghost...

https://www.boards.ie/discussion/comment/122624695#Comment_122624695

Cheers. It’s nice to know it helps a few people out.

I have the charge/discharge rates set to 100. The inverter fills the batteries at 5kW, so I get a good 20kWh over the 4 hours which would last the day easy enough. I usually have a decent bit in the battery, so only half the time will they take 20kWh and that’s only because I dump 10kWh before charging at 2am.

There is usually an EV charging over that period too.

The solar takes over for a lot of the day at present. I’d say on the darkest days, I might have squeaky bumb watching the battery at the end of the day, so adding a third battery and a DC-DC charger on the battery loop will see me getting through comfortably.

mjatkey

https://www.boards.ie/discussion/comment/122625402#Comment_122625402

Hi, just got the Seplos PC USB lead so was watching your video on the BMS and the parameter settings, quick couple of questions, where did you get the value of the settings from, and since you have changed them have you changed any since?

Thanks

...Ghost...

https://www.boards.ie/discussion/comment/122638077#Comment_122638077

I picked up settings recommendations from a diy solar forum contributor and I entered some "logical" values to match my cell capacity and desired use. Only a small number of settings needed adjustment, especially the cell capacity one, which depends on your cell size (280/300/304/305/315 etc). The settings you see on the BMS video are the settings I am using. All seems to be working just fine.

mjatkey

https://www.boards.ie/discussion/comment/122638507#Comment_122638507

Nice one, cheers.

The devils

https://www.boards.ie/discussion/comment/122623836#Comment_122623836

Love it

The devils

Just so vid well done 👏

DC999

https://www.boards.ie/discussion/comment/122625402#Comment_122625402

Could you pop in a link to your videos on the setup? Cheers

...Ghost...

https://www.boards.ie/discussion/comment/122666265#Comment_122666265

Here's video 1

https://m.youtube.com/watch?v=w3qSFP9MnBA&pp=ygUKU2VwbG9zIGRpeQ%3D%3D